They're made from a material called Supralsim 690 apparently. They were going to be Hardox but it would've taken longer to get and cost a lot more so I'm trying this as an alternative. Not sure how it will compare to Hardox in the arena, so will be interesting to see them after a battle. They're really just a temporary measure as I'm contemplating switching to a beater when I remake Drumroll's chassis out of ali, but unlike my previous temporary measure of bolted bar teeth, these should be a lot more robust.

Also the teeth are going to be set 120° apart compared to the 180° offset on the old drum. Means there will be more hits per revolution but I like the idea of this being a shredding drum (ala GutRip from the 1996 American RW vid) as much as a big impact drum.